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Biomedical subjects

R C Strunk

Publications and source records attributed to R C Strunk.

At least 73 records · Page 4Linked to original sources

Techniques of administration of metered-dose aerosolized drugs in asthmatic children.

The use of medications in metered-dose aerosol form in children with asthma has increased dramatically with the development of safer, inhaled beta 2-adrenergic agents and the inhaled corticosteroid, beclomethasone dipropionate. However, the most appropriate techniques of administration of these agents are presently unclear, and frequent inefficient use of these metered-dose inhalers results. We review the aerosol physiology literature to determine and recommend a most efficient inhalation technique for the use of these metered-dose aerosol devices.

Adrenergic beta-Agonists

Auriculotemporal syndrome in childhood.

Auriculotemporal syndrome, also known as Frey's syndrome, consists of the development of facial flushing or sweating over the distribution of the auriculotemporal nerve immediately following eating or drinking. It has been recognized in adults as a common postoperative complication of parotid-gland surgery or dorsal sympathectomy. The syndrome is uncommon in children. As its course is benign, it is important to recognize it, thus avoiding unnecessary referral and laboratory evaluation.

Female

Subjective psychological symptoms in outpatient asthmatic adolescents.

Outpatient adolescent asthmatics were studied using the Asthma Symptom Checklist (ASC) of Kinsman et al. The study showed that outpatient asthmatic adolescents are similar in many respects to older institutionalized asthmatics, except that in the former, psychological symptoms are more diffuse and recognition of respiratory symptoms is less severe. Further studies are needed to determine which psychological symptoms are most important in predicting prognosis in affected asthmatics or the development of "psychosomatic" asthma.

Adolescent

Binding of aggregated human gamma globulin by Raji cells: C1q will enhance only if it is dissociated from the C1 macromolecular complex.

The role of complement components in binding of aggregated human gamma globulin (AHG) to Raji cells was examined using the Raji cell radioimmunoassay. Incubation of AHG in normal human serum enhanced up to five-fold the binding of these complexes by Raji cells. This enhanced binding was medicated primarily by C3 receptors, however, as much as 30% of the enhanced binding was due to a heat-labile protein in serum. AHG incubated with serum-EDTA bound to Raji cells up to two-fold more than AHG incubated with unchelated serum. Since purified Clq also enhanced binding, binding of AHG after incubation with serum-EDTA was probably mediated by Clq. The enhancement effected by Clq occurred only if Clq bound first to AHG, not to the Raji cells, and if Clq bound in the absence of Clr and Cls. Speculations on a role for Clq in biological processes must consider whether the Clq in serum is available to participate. The results presented here suggest that whole serum activated by AHG contained only a small amount of Clq available for cross-linking of particles. Thus, the potential involvement of Clq in biological reactions in vivo is probably limited.

Antigen-Antibody Complex

Complement synthesis by guinea pig peritoneal macrophages: failure to detect chemical carcinogens.

In vitro production of the second and fourth components of complement (C2 and C4, respectively) by peritoneal macrophages from noninbred Hartley guinea pigs was tested after the animals had been inoculated with known carcinogens. The system demonstrated the capacity of N-nitrosodimethylamine to decrease C2 and C4 production. However, a similar decrease in C2 and C4 production was seen with only CCl4, 1 of the 10 chemical carcinogens studied. This system had little usefulness as a short-term screening procedure for the detection of carcinogenicity. The effect of the carcinogens on several other functions of peritoneal macrophages was also determined. The number of peritoneal exudate cells (PEC) was significantly lower in carcinogen-inoculated animals than in solvent-inoculated controls for three carcinogens: BeSO4, P < 0.005; CHCl3, P < 0.025; and CCl4, P < 0.01. However, the capacity of the PEC to adhere to plastic was decreased by only CHCl3 (P < 0.05), and adherent cells from all guinea pigs produced normal amounts of total secreted protein.

Animals

Inhibition of in vitro synthesis of the second (C2) and fourth (C4) components of complement in guinea pig peritoneal macrophages by a soybean oil emulsion.

Recently a soybean oil emulsion (Intralipid) (IL) has been released in the United States for use as a parenteral nutrient. The study reported here was undertaken to determine the effect of ingestion of IL on the synthesis and secretion of the second (C2) and fourth (C4) components of complement by guinea pig peritoneal macrophages in vitro. Cells exposed to IL had extensive Oil Red 0-positive granular-appearing accumulations of neutral lipid within the cytoplasm. Control cells did not stain with Oil Red 0. Incubation of the cells with concentrations of IL from 2.3--37.5 mg/100 ml resulted in a significant decrease in the production of both C2 and C4, which could not be explained by variability between plates. The decrease in total C2 or C4 production by cells incubated with IL for 4 hr was similar to the decrease in production by cells incubated with IL for 48 hr. Several lines of evidence indicated that the decrease of C2 or C4 was the result of decreased synthesis of these proteins and not interference of IL with the detection of the proteins or their secretion from the cells. Exposure of the cells to IL at all concentrations caused reduction of the number of cells having pseudopodia and a rounding-up of the cells. IL did not affect the rate of detachment of the cells from the plates through the 48-hr incubation period or the ability of the cells to exclude trypan blue. Total protein synthesis and total lysozyme production by control and IL-treated cells was similar.

Animals

Alternative pathway of complement activation in full term and premature infants.

Classical and alternative pathway complement levels were measured in the cord blood sera of 60 newly born infants, with weights ranging from 1200--4165 g. The impact of maternal illness and infant illness on the complement levels was also evaluated. The mean values for CH50, C3, C4, PH50, factor B, and properdin were all significantly less than normal adult levels (P less than 0.0001). All of the above determinations were significantly correlated with one another except for the relationship between properdin and factor B. CH50, PH50, C4, and properdin levels were significantly correlated with birth weight although there was much residual scatter. Neither maternal illness nor mild to moderate illness in the newborn altered the birth weight-complement relationships. Severe infant illness did significantly alter the relationship between birth weight and complement. However, the impact of this variable on the birth weight-complement relationships was not consistent among the various components. These inconsistencies and the small sample size preclude drawing any strong conclusions about severe illness and complement levels.

Adult

Immunofluorescence in group B streptococcal infection and idiopathic respiratory distress syndrome.

Immunofluorescence was performed on lung tissue obtained at necropsy from 18 newborn infants, including five with group B streptococcal (GBS) sepsis, seven with idiopathic respiratory distress syndrome (IRDS), and six control infants who died from other causes. Deposits of C3, IgG, and fibrin were found within hyaline membranes of infants who died with GBS sepsis or IRDS within 48 hours after birth. In some cases C4, factor B, and IgM were also observed. In five infants with IRDS who died more than five days after birth, immunofluorescent lung findings were less common and less intense. Hyaline membranes, attributed to mechanical ventilators and oxygen therapy in two infants who did not have GBS infection or IRDS, were negative for complement and immunoglobulins although fibrin was detected in one specimen. These data suggest that immunologic processes may contribute to the pathogenesis of certain types of acute lung injury, particularly in infants who die from GBS infection or IRDS during the early neonatal period.

Antigen-Antibody Complex

Alteration of the structure and function of guinea pig peritoneal macrophages by a soybean oil emulsion.

Studies in humans who have received Intralipid (IL) have demonstrated the presence of a fat pigment and fat droplets in reticuloendothelial phagocytic cells. Clinical data and in vitro studies suggest that these cells do not function normally. We have studied the effect of IL on the morphology and function of guinea pig peritoneal macrophages in vitro. Starch-induced macrophages were exposed to IL for up to 48 hours. Ingestion of increasing amounts of IL over the 48-hour period was confirmed by transmission electron microscopy and by oil red O stain. The uptake of the IL was associated with marked morphologic changes characterized by a decreased ability of the cells to spread and by a decrease in the number and degree of complexity of the membrane ruffles. The ingestion of IL also resulted in decreased capacity of the cells to associate with latex beads (5.7 mu in diameter) or Candida albicans and decreased capacity to adhere to and ingest sheep erythrocytes coated with IgG. After ingestion of latex beads 0.46 mu in diameter, which are similar in size to IL particles, macrophages had normal morphology and function, indicating that neither the morphologic nor functional abnormalities were due to a nonspecific effect of ingestion of small particles. Alterations of human reticuloendothelial macrophage function similar to the effects observed here could compromise host defense against infection.

Animals

Immune-complex-mediated glomerulonephritis and pulmonary hemorrhage simulating Goodpasture syndrome.

Two female children whose clinical presentations and renal light-microscopic findings were consistent with Goodpasture syndrome are described. Immunopathologic studies demonstrated granular deposition of immunoglobulins and complement, suggesting that the renal disease was mediated by circulating immune complexes and not by anti-glomerular basement membrane antibody. Anti-GBM antibody was absent in both patients. These patients represent the first report in children of idiopathic nephritis due to immune complexes with associated pulmonary hemorrhage. The findings raise some doubt as to the accuracy of previous reports of Goodpasture syndrome in children, and also demonstrate the diagnostic and therapeutic importance of evaluation the renal immunopathology in the child with nephritis and pulmonary hemorrhage.

Anti-Glomerular Basement Membrane Disease

Humoral immunity in experimental hyposplenism.

The immune response to an intravenous bolus of sheep erythrocytes, a large particulate antigen, was examined in weanling Sprague-Dawley rats after varying reduction in spleen size by splenic artery ligation (SAL) or partial amputation (pSx), and the results were compared with splenectomized (Sx) and sham-operated controls. Whereas SAL and pSx rats both produced higher 5 day (primary response) hemolysin antibody titers (P less than 0.001) than Sx rats, levels were lower (P less than 0.05) than in sham-operated rats with larger spleens (P less than 0.001). A similar heterophile pattern was seen in SAL rats at 22 days (secondary response). Within each group there was a positive correlation between splenic weight and serum hemolysin titer (r greater than 0.81) (P less than 0.001). Whereas spleen weight of sham-operated rats increased only 58%, splenic remnants in pSx rats enlarged 139% to 412%, with the greatest percentage of growth in the smallest remnants (25 mg) and the least in the largest remnants (200 mg). These data demonstrate a measurable immunologic advantage of splenic remnants (hyposplenism) over asplenism. This difference, although suboptimal as compared with that of a whole spleen (eusplenism), nonetheless may bolster body defenses to certain forms of bacterial sepsis.

Amputation, Surgical

Harvester ant sensitivity: in vitro and in vivo studies using whole body extracts and venom.

Harvester ant stings by Pogonomyrmex maricopa (Pm) or Pogonomyrmex rugosus (Pr) resulted in serious reactions in 8 patients, 4 with generalized reactions and 1 with large local reactions. Exposure to one species in the genus Pogonomyrmex (P) appeared to cross-sensitize ant-sensitive patients to other species in the same genus as evidenced by skin testing and leukocyte histamine release, but these patients were less sensitive to extracts from other stinging Hymenoptera, including bee, wasp, yellow jacket, hornet, and Formica ant. Pr ant venom was obtained by electrical stimulation of live ants for leukocyte histamine release studies. The venom preparation was considerably more effective in inducing histamine release than a body extract derived from gasters, the posterior abdominal segments. Rabbits immunized with an extract from one species produced precipitating antibodies against the injected extract withich cross-reacted with extracts from other species of harvester ant, but not with other stinging Hymenoptera. Humans and rabbits appear to react to certain genus-specific antigens present in Pogonomyrmex whole body extracts. Proper identification of the offending ant is crucial for proper testing and treatment of ant-sensitive patients.

Animals

Intrapatient variability in theophylline kinetics.

Seven asthmatic children had repeat determinations of theophylline pharmacokinetic measurements over three- to nine-month intervals. Significant intrapatient variability was found in the theophylline clearance and t1/2, which determine the dosage regimen necessary to provide given average, peak, and trough theophylline plasma levels. Repeat clearance values were, on average, 52% different from the original clearances, with a range of -57% to +142%. A single determination of theophylline kinetic measurements in any individual patient cannot be used routinely to predict future theophylline dosage regimens for that patient.

Adolescent